Joint tracking of the carrier phases of the signals received from different satellites
US6313789A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 1999 |
| Grant date | Nov 6, 2001 |
| Priority date | — |
| Expiry date | Jun 10, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2201/70715
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed are methods for increasing the fail-safety characteristics of tracking systems for navigation receivers which receive signals from many satellites. In an exemplary embodiment of the present invention, an individual PLL circuit is used to track the phase of each satellite's carrier signal, and a vector common tracking loop is used to track the disturbances of the carrier phases which are caused by one or more common sources, such as the movement of the receiver's antenna(s) and/or the phase fluctuation of the receiver's main reference oscillator. The vector common tracking loop uses phase information from all of the satellites being tracked, and for this reason can be made more wide-band than each of the individual PLL circuits. The wider bandwidth of the vector common tracking loop provides higher dynamic properties and more safe tracking when faint and weakening satellite signals are present. In another embodiment of the invention, the receiver receives the satellite signals from M.gtoreq.3 antennas mounted on a common object, and three common tracking loops are added to track the object's rotation about its three rotational axes. The common object may comprise any struc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.